Yeah I've been there. There are tons of ponies all over the island. Legend has it that in the mid to late 16th century, a Spanish ship crashed nearby and the horses onboard swam to safety on the island, which was uninhabited by humans. They continued to breed and eventually became their own breed, the Chincoteague pony. Since 1835 there has been an annual "Pony Penning Day" where people from the nearby island of Chincoteague go and round up the ponies and swim them over to Chincoteague. Since the 1940s, the ponies have been auctioned off to benefit the Chincoteague Volunteer Fire Department. The ponies who are not bought in the auction and the ones who are bought on "buy back" conditions (the person donates the money but agrees not to keep the pony) are bought back to Assateague so they can repopulate.